Venous valves are found within the vasculature of a mammal, particularly the veins. Venous valves prevent the backflow of blood during circulation. For example, venous valves help to fight backflow of blood in the legs caused by gravity pulling the blood away from the heart and back towards the feet of a person when standing. However, when venous valves fail to work properly, blood can flow backwards within the veins and pool in, for example, the legs. Such pooling of blood can cause the veins to become distended, thereby causing the venous valves to fail further. This progressively worsening disorder can lead to varicose veins and chronic venous insufficiency, which is painful and can lead to lower limb ulcerations.
Native venous valves are valves created by thin, overlapping leaflets of tissue that open in response to antegrade pressure, but close in response to retrograde pressure. These valves may be reconstructed in a surgical procedure, but are complicated to reconstruct. Known prosthetic venous valves that attempt to replicate the function of the native leaflet design are complicated to fabricate, may be damaged during percutaneous delivery, and tend to form thrombosis soon after implementation. Accordingly, there is a need for venous valve prostheses which can be delivered percutaneously. There is also a need for a venous valve prosthesis which can prevent thrombosis formation and be delivered to small veins.